Magnetically interlocked relay



March 22, 1966 R. HYlNK 3,242,284

MAGNET I CALLY I NTERLOCKED RELAY Filed Sept. 23, 1963 2 Sheets-Sheet l March 22, 1966 R. HYlNK MAGNETICALLY INTERLOCKED RELAY 2 Sheets-Sheet 2 Filed Sept. 25, 1963 illiiiili'lll'l'fl I IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII II United States Patent C) 3,242,284 MAGNETICALLY INTERLOCKED RELAY Roy Hyink, Wauwatosa, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Filed Sept. 23, 1963, Ser. No. 310,808 Claims. (Cl. 200-87) This invention relates to electrical relays which utilize magnetically operated reed switches, and more particularly to interlocked relays for the reversing control of an electric circuit.

The high degree of dependability of reed switches has made them extremely desirable for use as relays in electric control circuits. However, the sealed glass enclosure around the movable components of these switches has made mechanical interlocking between these switches very difiicult. I

It is therefore an object of this invention to provide a magnetic interlock between sealed, magnetically operated reed switches to prevent one switch from operating while another is operated.

This and other objects will be more fully understood in the following specification and claims when taken in conjunction with the drawings, wherein:

FIGURE 1 is an isometric view of a three pole, magnetically interlocked relay;

FIGURE 2 is a sectional view taken along the longitudinal center line as indicated by line 22 in FIG. 1;

FIG. 3 is a cross sectional View taken along the line 33 in FIG. 2;

FIG. 4 is an isometric view of a portion of FIG. 1;

FIG. 5 is a wiring diagram of one proposed use of the device; and

FIGS. 6a, 6b and 7 are vector diagrams illustrating various operating characteristics of the device.

With reference to the drawings, two pairs of pole pieces 2, 4 and 6, 8 are mounted between two frame members 10 made of an insulating material. The physical relationship between the pole pieces can best be seen in FIGS. 1 and 3 and will be described in greater detail later.

An iron cored coil 12 is mounted between the pole pieces 2 and 4 at one end thereof by a pair of screws 14, and a similar coil 16 is mounted between the pole pieces 6 and 8 at the other end by a pair of screws 18. Three reed switches 20, 22 and 24 are mounted in spaced apart relation between pole pieces 2 and 4 to one side of coil 12 and three like reed switches 26, 28 and 30 are similarly mounted between pole pieces 6 and 8 to the other side of coil 16, whereby the reed switch 26 lies to one side of reed switch 24 and the reed switches 28 and 30 lie in the spaces between reed switches 22 and 24 and 20 and 22, respectively. Pairs of wire terminal extensions 20a, 22a, 24a, 26a, 28a and 30a extend from the opposite ends of the respective reed switches and through insulating bushings 32 mounted in pole pieces 2, 4, 6 and 8. Bushings 32 serve the two-fold purpose of insulating the pole pieces from the terminals and holding the reed switches in place.

Referring to FIGS. 2 and 3, each pole piece 2 and 4 has three pole piece extensions 2a and 4a, respectively, mounted perpendicular thereto and in the same plane as reed switches 20, 22 and 24. The extensions 2a and 4a are also mounted on the same cross sectional planes as the reed switches 30, 28 and 26 of pole pieces 6 and 8, which also have extensions 6a and 8a mounted perpendicular thereto in the same plane as reed switches 30, 28 and 26 and on the same cross sectional planes as the reed switches 20, 22 and 24 of pole pieces 2 and 4. The extensions 2a, 4a, 6a and 8a extend inwardly from their respective pole pieces to points very close to their associated reed switches and their inner ends are beveled to create surfaces parallel to the sides of the enclosures of such reed switchces as seen in FIG. 3. As illustrated in FIG. 4, the last men- 3,242,284 Patented Mar. 22, 1966 tioned switches are positioned so that the fiat surfaces of the reeds are parallel to the longitudinal axes of a cooperating pair of extensions ,to cause the reeds to be forced apart by the magnetic field extending between the extensions when the latter are magnetized.

The relative position of the plane containing reed switches 26, 28 and 30 and pole piece extensions 6a and 8a to the plane containing reed switches 20, 22 and 24 and pole piece extensions 2a and 4a can best be seen in FIG. 3, where it can be seen that the first mentioned plane is at an angle to the perpendicular to the second mentioned plane. This angle may vary according to the operating characteristics of the reed switches used, but it is desirable to keep the angle between the two planes greater than but less than such angle being the obtuse angle formed between pole pieces 2 and 6, for reasons that will become apparent later.

In operation, the coils 12 and 16 of the device are connected to a suitable source of DC. supply voltage such as a battery 34 (FIG. 5). A pair of switches S1 and S2 are connected in the lines to coils 12 and 16, respectively, so that the coils may be energized independently of each other. The reed switches between one pair of pole pieces have their input ends connected to a three-phase supply source and their output ends connected to a load. The reed switches between the other pair of pole pieces have their input ends connected to the same three-phase supply source and their output ends are connected to the same load in phase reversed order.

Upon the closure of switch S1, current will flow from battery 34, through coil 12 and switch S1 and back to the battery, thus energizing coil 12 which creates a magnetic field in the pole pieces 2 and 4 and the reeds of reed switches 20, 22 and 24, thus causing the reeds to close and conduct current from lines L1, L2 and L3 to the load. The closed reeds increase the strength of the magnetic field created therein by eliminating the air gap upon their closure. This field is represented in direction and magnitude by vector Va in FIG. 6a. A magnetic field is also created in the extensions 2a and 4a which is represented in direction and magnitude by vector Vd in FIG. 6b and is of a lesser strength due to the air gap between the respective pole extensions.

Closure of switch S2 will energize coil 16 in the same manner as coil 12 was energized. The coil 16 creates a magnetic field in its pole pieces 6 and 8, their extensions 6a and 8a, and the reeds of reed switches 26, 28 and 30. The magnetic field created in the pole piece extensions 6a and 8a is of the same magnitude as the field, vector Va' (FIG. 6a), in extensions 2a and 4a, but is downward at the aforedescribed angle to the plane of switches 20, 22 and 24 as represented in direction and magnitude by the vector Vb in FIG. 6a, which creates a resultant field, represented in direction and magnitude by vector Vc in FIG. 6a, at an angle less than 45 to the first created field, vector Va, and thus has no opening effect upon the reeds.

The magnetic field, vector Va (FIG. 6b), created in the pole piece extensions 2a and 4a upon the energization of coil 12, is of the same magnitude as the field, vector Vb, created in the extensions 6a and 8a and acts upon the edges of the reeds of switches 26, 28 and 30 at the aforedescribed angle. The magnetic field, represented in direction and magnitude by vector Ve in FIG. 6b, created in the reeds of switches 26, 28 and 30 by the subsequent energization of coil 16 is nearly equal to the magnitude of the field, vector Vd, in the extensions 2a and 4a, and the two fields create a resultant field, represented in direction and magnitude by vector V in FIG. 6b. A magnetic field applied in this manner, that is, parallel to the reed width and almost perpendicular to the reed length, will cause the reeds of the last mentioned switches to tend to move apart, and thus remain apart. This effect is well known.

Upon reopening of switch S1 coil 12 will deenergize, and the magnetic field created in the pole pieces 2 and 4, extensions 2a and 4a and the reed switches 20, 22 and 24 dissipates, thereby permitting the latter to reopen. Wlth the subsidence of the magnetic field originally created by extensions 2a and 4a, and if switch S2 has remained closed, the reeds of switches 26, 28 and 30 will close due to the magnetic field created by the pole pieces 6 and 8 caused by coil 16. The magnetic field between the extensions 6a and 8a will now hold the reeds of switches 20, 22 and 24 open and prevent them from reclosing should coil 12 be energized while the coil 16 is still energized.

It will be understood that if the aforedescribed angle 18 too far from the perpendicular, that is 45 or more from theperpendicular, such angle therefor becoming an obtu se angle of 135 or more, a magnetic field created in the pole piece extensions causing the reeds of their cooperating reed switches to move apart, will be sufiiciently close to parallel to the switch operating field to close the reeds of those switches.

Similarly, if the aforedescribed angle was exactly perpendicular, and a first magnetic field as represented in direction and magnitude by vector Vg in FIG. 7, was created in the pole piece extensions in one plane to cause the reeds of their cooperating reed switches in the other plane to move apart, and a second magnetic field was created, represented in direction and magnitude by vector Vh in FIG. 7, by the subsequent energization of the second coil to cause these switches to close, the resultant field represented in direction and magnitude by vector Vi, in FIG. 7, would be 45 or less with the second field, vector Vh, and thus could overpower the field, vector Vg, and close these switches.

It is apparent from this description that whichever coil is energized first the reed switches extending between the pole pieces of that coil will close and the pole piece extensions between those pole pieces will prevent the other set of reed switches from closing upon energization of the other coil until the first energized coil is deenergized.

I claim:

1. An electromagnetic relay comprising first and second electromagnetic circuits each of which includes a core, an energizing winding on said core, spaced pole pieces connected to said core, and coaxial extensions extending toward each other from said pole pieces, and at least one enclosed reed switch mounted between the pole pieces of each magnetic circuit, and means supporting the electromagnetic circuits and reed switches so that the overlapped ends of the reeds of each of the latter are disposed between the pole extensions of the set of pole pieces of the other magnetic circuit and so that the energization of the coil of one magnetic circuit will efiect operation of the reed switch disposed between its pole pieces but prevent operation of the reed switch mounted between the pole pieces of the other magnetic circuit upon subsequent energization of the coil of the latter magnetic circuit while the coil ;f the first mentioned magnetic circuit remains energize 2. The combination according to claim 1, wherein the flat surfaces of the reeds of said reed switches are parallel to the longitudinal axes of their cooperating coaxial pole extensions.

3. The combination according to claim 2, wherein the longitudinal axis of the reed switch of one magnetic circuit is at an angle to the longitudinal axis of the cooperating coaxial pole extensions of the other magnetic circuit, said angle being greater than ninety degrees but less than one hundred thirty-five degrees.

4. The combination according to claim 3, wherein the inner ends of said pole extensions of one magnetic circuit are beveled at an angle to be parallel with the longitudinal axis of the cooperating reed switch of the other magnetic circuit.

5. In combination, a pair of electromagnetic circuits, each having an energizing means and a plurality of enclosed reed switches, said energizing means and said reed switches being mounted between a pair of pole pieces of their respective magnetic circuits, means for mounting said pair of magnetic circuits in an interlaced and criss-crossed relationship with each other, and means extending from each pole piece of said pair of pole pieces of each magnetic circuit in a coaxial relationship with each other to points near the overlapped ends of the reeds of the reed switches of the other magnetic circuit, whereby energizatlon of one magnetic circuit will effect operation of the reed switches of that circuit and the last mentioned means of that circuit will prevent operation of the reeds of the reed switches of the other magnetic circuit upon subsequent energization of the other magnetic circuit while the first energized circuit remains energized.

References Cited by the Examiner BERNARD A. GILHEANY, Primary Examiner.

5/1962 Dal Bianco et al. 200-93 X 

1. AN ELECTROMAGNETIC RELAY COMPRISING FIRST AND SECOND ELECTROMAGNETIC CIRCUITS EACH OF WHICH INCLUDES A CORE, AN ENERGIZING WINDING ON SAID CORE, SPACED POLE PIECES CONNECTED TO SAID CORE, AND COAXIAL EXTENSIONS EXTENDING TOWARD EACH OTHER FROM SAID POLE PIECES, AND AT LEAST ONE ENCLOSED REED SWITCH MOUNTED BETWEEN THE POLE PIECES OF EACH MAGNETIC CIRCUIT, AND MEANS SUPPORTING THE ELCTROMAGNETIC CIRCUITS AND REED SWITCHES SO THAT THE OVERLAPPED ENDS OF THE REEDS OF EACH OF THE LATTER ARE DISPOSED BETWEEN THE POLE EXTENSIONS OF THE SET OF POLE PIECES OF THE OTHER MAGNETIC CIRCUIT AND SO THAT THE ENERGIZATION OF THE COIL OF ONE MAGNETIC CIRCUIT WILL EFFECT OPERATION OF THE REED SWITCH DISPOSED BETWEEN ITS POLE PIECES BUT PREVENT OPERATION OF THE REED SWITCH MOUNTED BETWEEN THE POLE 